TY - GEN
T1 - The velocity of censorship
T2 - 22nd USENIX Security Symposium
AU - Zhu, Tao
AU - Phipps, David
AU - Pridgen, Adam
AU - Crandall, Jedidiah R.
AU - Wallach, Dan S.
N1 - Funding Information:
We would like to thank the anonymous reviewers and our shepherd, Nikita Borisov, for helpful feedback. We owe our deepest gratitude to Professors Stephanie Forrest, Christopher Bronk, and George Luger for their feedback and comments, and for encouraging us to go forward. We are also grateful to Ben Edwards for insightful discussions about potential future work. This material is based upon work supported by the National Science Foundation under Grant Nos. #0844880, #0905177, #1017602. Jed Crandall is also supported by the Defense Advanced Research Projects Agency CRASH program under grant #P-1070-113237.
Publisher Copyright:
copyright © 2013 USENIX Security Symposium.All right reserved.
PY - 2013
Y1 - 2013
N2 - Weibo and other popular Chinese microblogging sites are well known for exercising internal censorship, to comply with Chinese government requirements. This research seeks to quantify the mechanisms of this censorship: how fast and how comprehensively posts are deleted. Our analysis considered 2.38 million posts gathered over roughly two months in 2012, with our attention focused on repeatedly visiting "sensitive" users. This gives us a view of censorship events within minutes of their occurrence, albeit at a cost of our data no longer representing a random sample of the general Weibo population. We also have a larger 470 million post sampling from Weibo's public timeline, taken over a longer time period, that is more representative of a random sample. We found that deletions happen most heavily in the first hour after a post has been submitted. Focusing on original posts, not reposts/retweets, we observed that nearly 30% of the total deletion events occur within 5-30 minutes. Nearly 90% of the deletions happen within the first 24 hours. Leveraging our data, we also considered a variety of hypotheses about the mechanisms used by Weibo for censorship, such as the extent to which Weibo's censors use retrospective keyword-based censorship, and how repost/retweet popularity interacts with censorship. We also used natural language processing techniques to analyze which topics were more likely to be censored.
AB - Weibo and other popular Chinese microblogging sites are well known for exercising internal censorship, to comply with Chinese government requirements. This research seeks to quantify the mechanisms of this censorship: how fast and how comprehensively posts are deleted. Our analysis considered 2.38 million posts gathered over roughly two months in 2012, with our attention focused on repeatedly visiting "sensitive" users. This gives us a view of censorship events within minutes of their occurrence, albeit at a cost of our data no longer representing a random sample of the general Weibo population. We also have a larger 470 million post sampling from Weibo's public timeline, taken over a longer time period, that is more representative of a random sample. We found that deletions happen most heavily in the first hour after a post has been submitted. Focusing on original posts, not reposts/retweets, we observed that nearly 30% of the total deletion events occur within 5-30 minutes. Nearly 90% of the deletions happen within the first 24 hours. Leveraging our data, we also considered a variety of hypotheses about the mechanisms used by Weibo for censorship, such as the extent to which Weibo's censors use retrospective keyword-based censorship, and how repost/retweet popularity interacts with censorship. We also used natural language processing techniques to analyze which topics were more likely to be censored.
UR - http://www.scopus.com/inward/record.url?scp=85076283490&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85076283490&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85076283490
T3 - Proceedings of the 22nd USENIX Security Symposium
SP - 227
EP - 240
BT - Proceedings of the 22nd USENIX Security Symposium
PB - USENIX Association
Y2 - 14 August 2013 through 16 August 2013
ER -